1. Field of the Invention
This invention relates to an intravascular balloon occlusion device, a portion of which is adapted to be positioned inside a vessel during surgical procedures and, more particularly, to an aortic balloon occlusion device wherein the balloon is adapted to seal portions of the aorta while blood flows therethrough.
2. Description of the Related Art
A current trend in coronary bypass surgery is to utilize a minimally invasive surgical procedure. In such a procedure, there is no need to open the chest through a conventional open heart surgical procedure. Rather, multiple access points are created for the receipt of the necessary surgical tools. This procedure has the distinct advantages of minimizing trauma to the tissue surrounding the heart and chest cavity.
In performing a coronary bypass, one end of a bypass vein is attached to the ascending aorta while the other end of the bypass artery is attached to the coronary artery, downstream from the blockage or occlusion. In attaching one end of the bypass artery to the aorta, it is necessary to create a hole in the aorta, providing an aperture for suturing the end of the bypass artery. The typical procedure is to cross clamp the aorta to stop the blood flow. A problem with this procedure is that it is desirable to continue blood flow through the aorta at all times in order to continue blood flow throughout the body. However, if the surgeon were to punch a hole in the aorta while the blood was flowing therethrough, some blood would flow out the hole, thereby flooding the surgical field with blood and increasing the patient""s blood loss during the surgical procedure.
One problem with the prior art coronary artery bypass graft procedures and instruments used therefore is providing means for sealing the aorta so that the hole punches and grafts can be formed therein while continuing the flow of blood through the aorta.
The intravascular balloon occlusion device according to the invention overcomes the problems of the prior art by providing occlusion means such as a balloon on a body for effectively sealing a portion of the side wall of the aorta from the hollow interior thereof during the anastomosis process. These advantages are all realized while blood continues to flow through the aorta.
The invention comprises an intravascular occlusion device comprising an occlusion device body having a proximal end and a distal end. Preferably, the proximal end is closed so that fluid does not flow from the occlusion device body into a vessel. A connector is provided on the proximal end of the body and a first inflatable member is provided on the exterior surface of the distal end of the body. The inflatable member is adapted for inflation between a retracted state and an expanded state. A first inflation lumen is formed in the body. One end of the lumen is fluidly connected to the first inflatable member. Preferably, the second end of the lumen extends to the connector. The occlusion device according to the invention is adapted to be inserted into an aperture formed in a side wall of a blood vessel when the first inflatable member is in the retracted state. Next, the first inflatable member is expanded so that the inflatable member can be drawn against the interior of the vessel and substantially seal the side wall aperture from the fluid flowing through the vessel.
Preferably, the device includes a second inflatable member provided on the exterior surface of the balloon as a back up to the first member in the event of failure of the first inflatable member. The second inflatable member is independently inflated by fluid passing through a second inflation lumen formed in the body.
In an alternative embodiment, an irrigation aperture is provided in the body of the device proximally of the first and second inflatable members. An irrigation lumen extends to the body from the irrigation aperture to the proximal end of the body, preferably the connector. With this structure, the user can irrigate the area proximally of the first inflation member thereby keeping the surgical field clear.
In an alternative embodiment, a high pressure balloon is provided on the body of the device proximally of the first and second inflation members. Inflation of the high pressure balloon is controlled through a stent inflation lumen extending through the body. The high pressure balloon is used in assisting in the anastomosis process to expand a stent-like anastomosis device which telescopically surrounds the high pressure balloon.
The occlusion device according to the invention can also be adapted for use with a modified vessel punch. Punches are typically used to form an aperture in the side wall of a vessel. In this case, the punch comprises a hollow body having a cutting flange provided at one end thereof and a head member slideably mounted inside the hollow body. The head member is adapted to cooperate with the circular flange and cut a circular aperture in the vessel wall. The hollow body of the punch is dimensioned to simultaneously receive both the head member and the occlusion device. With this structure, the aperture can be formed in the vessel wall with the punch, and then the occlusion device can be inserted into the vessel without withdrawing the punch from the vessel aperture.
In another aspect, the invention relates to a method of performing a coronary artery bypass graft comprising the steps of providing an occlusion device as described above and providing a graft vessel. An incision is formed in the side wall of the aorta, and the distal end of the occlusion device is inserted through the incision a sufficient distance until the first inflatable member, in the retracted state, is received in the aorta. Next, fluid is supplied to the first inflatable member through the inflation lumen, thereby expanding the inflatable member inside the aorta. The occlusion device is withdrawn from the aorta until the expanded first inflatable member contacts the interior of the sidewall of the aorta and substantially seals the incision from fluid flowing therethrough. The graft vessel is telescopically mounted on the exterior of the occlusion device body and then slid into position adjacent the incision. Next, the vessel is sutured to the aorta or xe2x80x9cstentedxe2x80x9d into place using the high pressure balloon. Finally, the fluid from the first inflatable member is withdrawn causing the inflatable member to assume the retracted state, and then the occlusion device is withdrawn from the aorta and graft vessel.